Hybrid vehicles, pure electric vehicles, fuel cell vehicles, and the like, travel while having an electric device such as an inverter operating with power from a high voltage power supply. Therefore, when such vehicles receive a significant impact of a crash or the like that exceeds a tolerable impact level of their electric devices, the electric devices may be damaged, and an electric power at a high voltage may leak, depending on the extent of the damage to the electric system. In order to prevent such an occurrence, it is necessary to promptly detect a crash of a vehicle, to promptly shut down the power supply from a power source when the crash occurs, and to promptly discharge the charges in a high-voltage capacitor.
The Patent Document 1 mentioned below discloses a structure in which a conductive film is attached on the inner surface of the cap of a case for accommodating an inverter, the conductive film being to be electrically disconnected when the cap is deformed. An ECU determines the value I of a current flowing through the conductive film to see whether or not the current value I is substantially zero. When the current value I is substantially zero, it is determined that the inverter has received an impact, and the system main relay is turned off to shut down the power from the battery. In addition, the inverter is stopped operating to put the motor generator in a non-operating state so that no power is generated.